static headspace (hs) dynamic headspace spray-and-trap (st) spme membrane inlet

Download Static Headspace (HS)  Dynamic Headspace  Spray-and-Trap (ST)  SPME  Membrane Inlet

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Extraction Methods. Static Headspace (HS) Dynamic Headspace Spray-and-Trap (ST) SPME Membrane Inlet. Purge-and-Trap. Purge-and-Trap Method. Advantage : More sensitive than HS. Drawback : 1. Foaming and slowness of the purging step - PowerPoint PPT Presentation

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  • Static Headspace (HS) Dynamic Headspace Spray-and-Trap (ST) SPME Membrane InletPurge-and-TrapExtraction Methods

  • Advantage : More sensitive than HSDrawback : 1. Foaming and slowness of the purging step 2. Large sample volume and long purging time (10~30 min)

    Purge-and-Trap Method

  • Experimental AimTo construct an automated ST-GC system for on-line determination of dissolved VOCs in water.

  • Carboxen 1000Carboxen 10031/16Micro-sorbent Trap

  • Spray-and-Trap Device

  • Cleaning

  • Sampling

  • Mode A

  • Mode B

  • Injection

  • 2. Amount of sample3. Amount of extraction gas that is sampled.Sensitivity of Mode A1. Sprying conditionA. Size of dropletB. Extraction gas flow rateC. Design of nozzleD. Introducing a limited amount of sample and extraction gasSensitivity of Mode A

  • Mode A VS. Mode BA

  • Purge-and-Trap Device

  • Analytical conditions for ST and PT

  • Recoveries of ST methodsRecovery =

  • DL, R.S.D, and R2 for BTEX

  • Chromatograms of ST-GC-ECDCHCl3CCl4CH2Br2CHCl=CCl2CHBrCl2CCl2=CCl2

  • Conclusion An automated spray-and-trap device was built in the laboratory.

    The studied ST method was validated in comparison with classic PT: recoveries precision, and linearity.

    The ST method shows a fast response to abrupt changes in sample quality, which makes it suitable for on-site monitoring of a water body.